1. Field of the Invention
The present invention generally relates to fuel filter nipples, and more particularly, is concerned with a one piece nipple which can be directly brazed to a fuel filter housing.
2. Description of the Relevant Art
Fuel filters require some type of connection between the fuel filter housing and the fuel hose. This connection must be leak-proof and sturdy, yet easy to assemble onto the housing. Also, it must be simple to put the hose onto the connection, but the hose must then remain fixed.
For this purpose, fuel filter nipples are generally used. A depiction of a typical fuel filter nipple 100 is set forth in FIG. 3. The nipple is brazed onto a separate washer 110 which is, in turn, brazed onto the fuel filter housing 120.
This type of nipple assembly has several inherent and practical problems. Due to its design, it cannot fit directly onto a filter housing, but needs a separate washer. The use of the washer itself causes many problems. It necessitates the use of extra time and money to braze the washer separately. Also, the metal of the washer must be the same metal or alloy as the housing and the nipple. Otherwise, if three different metals are used, they will have different coefficients of expansion, thus causing leakage between the housing and the washer, and between the washer and the nipple.
The housing with the nipple attached is vulnerable to breakage during handling, assembly and use. If the brazed attachment between housing and nipple is not strong enough, the sheer angle at which the nipple must be attached makes breakage likely if an object knocks against it.
A practical disadvantage of this typical fuel nipple is that it is often mistakenly brazed to the washer backwards. Although one end of the nipple is tapered, the difference in appearance is so slight that, during assembly, workers have confused the ends and brazed the wrong one. This necessitates rejection of the assembly since the flange, which holds the hose in place on the body of the nipple, is off center.
Therefore, it would be desirable to have a nipple which would eliminate the need for a washer, would be more resistant to breakage, would lessen leakage problems, and which would be impossible to inadvertently assemble to the housing incorrectly.